I used to go and flatten my nose against that window and absorb all I could of his art. It changed my life. I saw art then as I wanted to see it.

This quote is referring to someone looking at the work of an artist. The person would press their nose against the window to get a better look and learn from what the artist had created. The person found it inspiring and it changed the way they looked at art. In other words, the person was able to appreciate art in their own special way after looking at the artist’s work through the window.